President Donald Trump’s UK ambassador holds investments in the companies set to develop flagship tech projects across the country.

U.S. financial records show that Warren Stephens’ family-owned investment firm owns shares worth at least $800 million in tech companies, including $169 million in Microsoft, $118 million in Nvidia, and $114 million in Alphabet (Google’s parent company) – all of which have announced major projects in the UK this week.

Trump is currently in the UK for a second state visit, and is being accompanied by tech and finance executives.

These U.S. firms have announced £31 billion in UK investments, giving them the opportunity to develop critical tech infrastructure, including data centres and computing capacity.

This tech partnership – dubbed the ‘Tech Prosperity Deal’ – has been negotiated for several months between the Trump administration and Keir Starmer’s Labour government.

Since his inauguration in January, Trump has vocally advocated for the interests of big tech companies, many of which are his donors. Google, Nvidia, Meta, and Amazon gave $1 million each to Trump’s inauguration ceremony, while Microsoft shelled out $750,000.

The CEOs of Apple, ChatGPT creator OpenAI, and chip manufacturer Nvidia – the world’s largest publicly-listed company – have joined Trump on his visit to the UK.

“Trump’s state visit is being used to cement the power of the big tech oligarchs and their super rich financial investors over the UK,” said Nick Dearden, director of the campaign group Global Justice Now. 

“Trump has always been a president for the oligarchs, using tariffs as a form of economic warfare to force governments to hand over their sovereignty to tax and regulate the big tech robber barons. What would previously have been regarded as outright corruption is now just business as usual in Trump’s White House.”

This tech deal follows an agreement signed in May that opened up the UK market to U.S. agricultural products. As revealed by DeSmog, Stephens played a key role in pushing through this agreement while holding shares worth at least $250 million in firms that potentially stand to benefit.

Stephens, a billionaire, gave $4 million to Trump’s inauguration fund on the same day that he was nominated for the ambassadorial role. Prior to starting his new job, Stephens stated in his ethics undertakings that he would remain a shareholder at Stephens Inc. but would resign from a management position and would not participate in any matter as ambassador that has a “direct predictable effect” on the financial interests of the company, unless he obtains a written waiver.

According to Stephens Inc.’s financial filings, its investments in big tech companies have increased in the period from the end of March to the end of June.

There is no evidence that Stephens used his diplomatic position to orchestrate trade deals that would boost his family’s investments or benefit the firms in their portfolio.

The Stephens Inc. and the U.S. embassy in London were approached for comment.

Big Tech’s Climate Impact

Several of the newly-announced UK investments are in large data centres – sites to power artificial intelligence (AI).

Data centres require large amounts of energy and water – a query in ChatGPT requires about 10 times the computing power of a Google search – leading to major concerns about their climate and environmental impacts.

The average data centre uses enough energy to power roughly 5,000 UK homes, and between 11 million and 19 million litres of water per day, the same as a town of 30,000 to 50,000 people. There are 480 data centres in the UK, with another 100 planned for the next five years.

The anticipated growth of these facilities has led to predictions that globally they will soon account for the same amount of power demand as that of Japan. 

Google’s greenhouse gas emissions were 48 percent higher in 2023 than in 2019, driven by its data centres. Its parent company Alphabet – which opened a £735 million data centre in Hertfordshire with Chancellor Rachel Reeves on Tuesday – announced a £5 billion investment in UK-based AI research and infrastructure this week.

As revealed by DeSmog, at the 2025 Hill & Valley Forum, Alphabet’s president and chief investment officer Ruth Porat praised a speech from Trump’s Interior Secretary Doug Burgum, who slammed Silicon Valley’s support of the so-called “climate extremist agenda” and pushed for the expansion of “incredibly clean” coal plants and other fossil fuels to power data centres.

Trump has vowed to “drill, baby, drill” for oil and gas, has called climate change a “hoax”, and has once again pledged to pull the U.S. out of the flagship 2015 Paris Agreement, which established a global ambition to limit global warming to 1.5C above pre-industrial levels.

Leading tech figures have suggested that the energy requirements of data centres can keep alive global demand for fossil fuels. They have attempted to justify this by speculatively claiming that the power of AI will be able to dramatically reduce emissions.

Stephens Inc., now run by Stephen Warren’s sons, also has considerable fossil fuel investments, including in some of the world’s biggest oil and gas producers.

Google claims it has signed a deal with Shell to supply “95 percent carbon-free energy” for its UK investments. The tech giant committed in 2020 that all of its operations would be powered by carbon-free energy by 2030.

“Starmer needs to learn that appeasing [Trump] doesn’t work,” said Dearden. “So this week we’re going to see the UK sign a bunch of deals which will provide very few jobs, cost us a fortune in emissions and pollution, and erode our sovereignty. It might all look nice short term – long term it turns us into a vassal state for these corporate titans.”